= y command
        .re-display all lines of the hiddlen line set.
        .[,b][.s] parameter is not supported
        .n for xx-xx pattern is not supported

      (1) y[n] pattern

        .following 2 set of hidden lines are unhidden

            0001000|A
            y2     |-      2 line excluded ------------------
            0004000|D
            0005000|E
            -------|-      1 line excluded ------------------
            0007000|G
            -------|-      2 line excluded ------------------
            0010000|J
            -------|-      1 line excluded ------------------
            0012000|L
        ===>
            0001000|A
            0002000|B
            0003000|C
            0004000|D
            0005000|E
            0006000|F
            0007000|G
            -------|-      2 line excluded ----------------
            0010000|J
            -------|-      1 line excluded ----------------
            0012000|L

      (2) yy-yy pattern

        .all hidden part of the range area unhidden

            0001000|A
            -------|-      2 line excluded ----------------
            0004000|D
            0005000|E
            yy     |-      1 line excluded ----------------
            0007000|G
            -------|-      2 line excluded ----------------
            0010000|J
            yy     |-      1 line excluded ----------------
            0012000|L
        ===>
            0001000|A
            -------|-      2 line excluded ----------------
            0004000|D
            0005000|E
            0006000|F
            0007000|G
            0008000|H
            0009000|I
            0010000|J
            0011000|K
            0012000|L